The Effect of Superficial Cervical Block Application on Postoperative Opioid Consumption in Patients Undergoing Anterior Cervical Discectomy Surgery

Overview

This randomized controlled trial aims to evaluate the effect of superficial cervical block on postoperative opioid consumption in patients undergoing anterior cervical discectomy surgery. Postoperative pain significantly impacts recovery and patient comfort in this type of surgery, where symptoms such as swallowing difficulties, occipito-cervical pain, and positional discomfort are common. While opioids are effective for pain control, their side effects, such as nausea, vomiting, and respiratory depression, may lead to complications, especially in cervical surgeries with potential airway risks. Superficial cervical block is a simple and safe regional anesthesia technique proven effective in managing pain after thyroid and carotid surgeries. However, its potential benefits in anterior cervical discectomy surgeries have not been extensively studied. Our hypothesis is that superficial cervical block can reduce postoperative opioid use and provide effective pain management for these patients. Additionally, investigators aim to compare opioid-related side effects and postoperative pain scores between groups with and without the block.

This prospective, randomized, double-blind, controlled trial is conducted at Medipol Mega University Hospital in patients undergoing microscopic anterior cervical discectomy and fusion (ACDF). The primary objective is to assess the effect of a superficial cervical plexus block on the incidence of requiring postoperative rescue analgesia. Secondary objectives are total cumulative tramadol consumption, the incidence of opioid-related adverse events (nausea, vomiting, pruritus) and postoperative Numerical Rating Scale (NRS) pain scores at rest and on movement. Patient selection: Eligible participants are aged 18-70 years with an American Society of Anesthesiologists (ASA) physical status of I-II, scheduled for unilateral single- or two-level microscopic ACDF under general anaesthesia. Exclusion criteria are bleeding diathesis, anticoagulant therapy, known local anaesthetic or opioid allergy, a history of chronic pain, infection of the skin at the puncture site, and refusal to participate. Study groups: Participants are randomly assigned to two groups. Group 1 (control) receives no regional block. Group 2 (intervention) receives a right-sided superficial cervical plexus block at the end of surgery, before awakening. Anaesthesia management: General anaesthesia is induced with intravenous propofol (2-3 mg/kg), fentanyl (1.5 mcg/kg) and rocuronium (0.6 mg/kg), and maintained with a remifentanil infusion (0.05-2 mcg/kg/min) and desflurane in an air-oxygen mixture. A remifentanil bolus (0.5 mcg/kg) is given if heart rate or mean arterial pressure rises more than 20% above the pre-induction baseline. All patients receive intravenous ondansetron 4 mg, paracetamol 1 g and tramadol 100 mg thirty minutes before surgery. Surgery is performed by the same team through a right-sided anterior cervical approach with a 3-4 cm transverse skin incision; no local anaesthetic or adrenaline infiltration is performed at the incision site in either group. Discectomy, neural decompression and interbody cage insertion are performed under the operating microscope. Block technique: Under ultrasound guidance, 20 mL of 0.25% bupivacaine is injected superficial to the investing layer of the deep cervical fascia at the posterior border of the sternocleidomastoid muscle. Postoperative evaluation: NRS pain scores at rest and on movement are recorded at 1, 3, 6, 12, 18 and 24 hours after surgery. Rescue analgesia (1 mg/kg intravenous tramadol) is given if the NRS score is 4 or above. Postoperative opioid consumption, adverse events (nausea, vomiting, pruritus) and block-related complications are recorded over the first 24 postoperative hours.